Wednesday 8 December 2021

Serial Perl Revisited

I'd posted this item on creating a custom serial driver / interface in  PERL a few years ago, and needing to revisit it for another project, I found that there was now an issue with running the Win32::Serial module on 64-bit Windows, Windows 10 specifically.

The problem was, when I ran some Perl that previously worked for me, it now failed when querying a serial port with an error like this;

error: Second Read attempted before First is done at line 47.

Some Google-Fu later, I found a reference to the issue on PerlMonks, and a link by user cr8josh to the fix by Christopher Oicles which is published here.

It looks like there's a risk that the rt.cpan site will close, so I'm reproducing the fix here for my own future sanity;